Yamaha Star V-Max Forum :: Topic: EXUP removal mod (1/3)

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TOPIC: EXUP removal mod

EXUP removal mod 9 months 4 weeks ago #1

Just got done reading all of the posts for the exup removal mod from over a year ago and am just wondering if everyone still agrees that it is a worthwhile mod for a stock set up. Thanks in advance for your thoughtful and knowledgeable feedback	doughboy OFFLINE Junior Max Posts: 78 Thank you received: 19
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Re: EXUP removal mod 9 months 4 weeks ago #2

The only reason mine is gone is cause I left it attached to the cat upon removal of the cat. But, Stock...why not just leave it be. Bike is a Monster in stock form.	Remaxed NOW ONLINE Platinum Max Posts: 2491 Thank you received: 1135
Don't sweat the small stuff... it aint worth it! lol The administrator has disabled public write access.

Re: EXUP removal mod 9 months 4 weeks ago #3

I believe Tim Nash has confirmed that the EXUP is not used on the VMax to increase power (TQ) like it is on other bikes. It's used to meet standards for emissions mostly, and perhaps noise as well. There was actually a slight power increase with it disconnected.	itgoes NOW ONLINE Platinum Max Posts: 4957 Thank you received: 2398
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Re: EXUP removal mod 9 months 4 weeks ago #4

From reading the posts most people said they felt a slight increase in torque with the exup removed on a stock bike but some felt that it might cause the bike to run lean. Was just wondering if there were any definite conclusions from the people that did the mod.	doughboy OFFLINE Junior Max Posts: 78 Thank you received: 19
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Re: EXUP removal mod 9 months 4 weeks ago #5

Mine was removed within the first 2 months, and it was done at Tim's where the dyno showed 7ft lbs more torque in the lower rpms. The seat of the pants dyno also told me to leave it unhooked until I got my xpipe..	No_Max NOW ONLINE Platinum Max Posts: 2728 Thank you received: 2128
Lean & Mean it in every corner of your life... If it wasn't for us the fast lane would rust... V4'S are music to the seat of my pants... Get your V-Max ECU Re-Flashed to Full Power! Last Edit: 9 months 4 weeks ago by No_Max. The administrator has disabled public write access.

Re: EXUP removal mod 9 months 4 weeks ago #6

EXUP Testing: Open Verses Closed. Proof it kills horsepower.	VMaxGuru OFFLINE Site Sponsor Posts: 980 Thank you received: 1347
Ride soon, Tim Nash GuruedGear The administrator has disabled public write access. The following user(s) said Thank You: No_Max

Re: EXUP removal mod 9 months 4 weeks ago #7

This chart shows an increase of almost 30 HP with it open? Am I understanding this right? I thought most Vmax had around 170 to 180 HP stock anways. VMaxGuru wrote: EXUP Testing: Open Verses Closed. Proof it kills horsepower.	Comtek OFFLINE Senior Max Posts: 246 Thank you received: 71
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Re: EXUP removal mod 9 months 4 weeks ago #8

I was confused by the graph at first but I think I understand it now. The graph does not mean "EXUP Installed" or "EXUP Not Installed". It means "EXUP Valve Open" and "EXUP Valve Closed". The ECU opens the EXUP valve around 4500 RPM I think (not sure of exact RPM), so look at the curve above 4500 RPM with the EXUP valve open and below 4500 RPM with the EXUP valve closed to see what the bike does in stock form. His curve is an artificial condition which he imposed by overriding the EXUP control to do his test. If I am wrong in my interpretation of the graph, I am certain that someone will correct me.

MRMILSTAR
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Re: EXUP removal mod 9 months 4 weeks ago #9

I only disconected the exup, nothing was removed.	BAD2MX OFFLINE Junior Max Posts: 74 Thank you received: 5
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Re: EXUP removal mod 9 months 4 weeks ago #10

MRMILSTAR wrote:

I was confused by the graph at first but I think I understand it now. The graph does not mean "EXUP Installed" or "EXUP Not Installed". It means "EXUP Valve Open" and "EXUP Valve Closed". The ECU opens the EXUP valve around 4500 RPM I think (not sure of exact RPM), so look at the curve above 4500 RPM with the EXUP valve open and below 4500 RPM with the EXUP valve closed to see what the bike does in stock form. His curve is an artificial condition which he imposed by overriding the EXUP control to do his test. If I am wrong in my interpretation of the graph, I am certain that someone will correct me.

I closed the EXUP and did a dyno run then I opened the EXUP and did another run. This was the difference between runs. The ECU opens the EXUP when the bike is in 4th or 5th gear, therefore you never really see its effect on HP as most bikes are dynoed in 4th or 5th. Both runs I did was 1st runs and not peak HP runs which was usually the 4th consecutive dyno run on my stock bike. I was just proving the point. Stock the bike would peak around ~173RWHP.

The actual stock ECU EXUP settings: